How to Lay Tile Patio

Rough up the surface of the concrete and remove any sealer or curing compound with a bead blaster. Slowly push the blaster across the floor as it shoots metal balls at the floor and vacuums them up. The impact will wear off any coatings and create a rough surface for the mortar. Snap chalk lines at the middle of opposite sides. Measure 3 feet from the intersection along one line and 4 feet along the other line. If the distance between the points is 5 feet, the lines are square. If not, reposition one of the lines until it is square with the other.

Add about half the water called for on the mortar box or bag. Slowly add the rest while mixing at slow speed with a paddle designed for mortar (not paint). After mixing let the mortar rest for 10 minutes, then mix again before use. Start at the intersection of the chalk lines and spread mortar over an 8- to 10-square-foot area. Press the mortar into the slab with a trowel held at a shallow angle. Comb the mortar in straight lines, holding the trowel at at 35-degree angle to the slab and forcing the teeth of the trowel against the concrete. This ensures you have the right amount of mortar on the concrete. The size of the notch should equal the thickness of the tile.

Start at the intersection of the lines, put the tile in the mortar, and twist it slightly to embed it in the mortar. Pull up the tile and look at the back. Parallel mortar lines mean the bed isn’t thick enough; dry areas means the mortar is too old. In either event scrape up the mortar and reapply. If the bed was too thin, hold the trowel at a greater angle when you comb out the mortar.

When the mortar bed is right, lay the first two tiles and a couple of spacers placed on end between them. Lay all the tiles in the mortared area. Lay a short 2x4 on top of the tiles and lightly tap with a rubber mallet to level the tiles. Lay mortar over an area the same size as the first and set tiles in it. Check the back of a tile occasionally to make sure you’re laying enough mortar. Work area by area until you tile the entire patio. At the edge of the patio, you’ll probably need to cut tiles to fit. Mark where you need to make cuts and cut with either a tile saw or a snap cutter.

Remove the spacers. Mix the grout at slow speed in a 5-gallon bucket with a mortar paddle and a ½-inch drill. Let the grout rest for 10 to 15 minutes, then remix. Apply the grout with a rubber grout float held at a shallow angle. Press the grout into the joints to fill them. For joints wider than 3/8 inch, use a grout bag. Fill the joints between the patio and any structures with caulk instead of grout.

Hold the grout float at a steep angle. Diagonally sweep the float across the tiles so the float doesn’t dip into the joints. Immediately wash off the haze left by the grout before it dries. Rinse repeatedly and keep the water clean in order to remove the haze.

Let the grout dam cure by spraying it with a mist (don’t drench it) several times a day for three days. If the patio receives direct sunlight, cover it with plastic sheeting between mistings. Check the directions that come with the sealer to see how long you should wait before applying it. Apply the sealer with a sponge mob and wipe up the excess before it dries. Follow the manufacturer’s directions for the number of applications.